Electrosurgical systems are used by physicians to perform specific functions during surgical procedures. For example, in an ablation mode electrosurgical systems use high frequency electrical energy to remove soft tissue such as sinus tissue, adipose tissue or other tissue such as meniscus, or cartilage or synovial tissue in a joint.
Conventional electrosurgical methods are widely used because they generally achieve hemostasis and reduce patient bleeding associated with tissue cutting operations while improving the surgeon's visibility of the treatment area. Many of the electrosurgical devices used in electrosurgery include a method of removing fluid, debris and bubbles from the field, so as to improve the clinician's visibility around the target tissue area. However, in the case of some electrosurgical devices where sufficient fluid is required to achieve certain clinical effects, such as ablation, fluid removal needs to be balanced or targeted in optimal locations. This may allow sufficient fluid for vapor layer or plasma generation while minimizing debris and bubbles in the field. Many devices also make use of a screen-type active electrode which is typically cut, or etched, from a sheet of conductive material. These electrosurgical devices and procedures, however, may suffer from a number of disadvantages. For example, screen-type active electrodes typically require some method of securement to an insulative body and furthermore to the distal tip of the device itself. Failure to adequately secure the screen electrode to the insulative body may result in improper device function.
Prior attempts to secure the screen active electrode to the insulative body have involved mechanical, thermal, and chemical means or various combinations thereof. Numerous mechanical forms of securement have been utilized, while adhesives have been used as a chemical form of joining, and welding the screen may provide a thermal method of joining. These mechanical joining methods may also include the use of plastic, or non-recoverable, deformations of the materials being used for securement. However, even in combination with other joining methods, all methods for fixation provide solutions that typically are challenged over extended periods of use, due to thermal degradation and plasma degradation. Optimum positioning of the screen electrode fixation with these methods of degradation therefore must be incorporated.
Accordingly, devices and methods which allow targeted fluid aspiration relative to ablation surfaces or edges are desired. Additionally, devices for the securement of flat screen active electrodes to the insulative body of an electrosurgical instrument while maintaining electrical connections through the insulative body are desired. In particular, mechanical methods for providing durable securement of an electrically connected screen active electrode to the insulative body at the distal tip of an electrosurgical device, while providing enhanced electrosurgical operating parameters are desired.